154 research outputs found
Contrasting Observed Atmospheric Responses to Tropical Sea Surface Temperature Warming Patterns
AM was funded by a NERC doctoral training partnership grant (NE/L002558/1). This study was funded as part of NERC's support of the National Center for Earth Observation: HB and PIP were supported by grant number NE/R016518/1.Equilibrium climate sensitivity (ECS) is a theoretical concept which describes the change in global mean surface temperature that results from a sustained doubling of atmospheric CO2. Current ECS estimates range from âŒ1.8 to 5.6 K, reflecting uncertainties in climate feedbacks. The sensitivity of the lower (1,000â700 hPa) and upper (500â200 hPa) troposphere to changes in spatial patterns of tropical sea surface temperature (SST) have been proposed by recent model studies as key feedbacks controlling climate sensitivity. We examine empirical evidence for these proposed mechanisms using 14 years of satellite data. We examine the response of temperature and humidity profiles, clouds, and topâofâtheâatmosphere radiation to relative warming in tropical ocean regions when there is either strong convection or subsidence. We find warmer SSTs in regions of strong subsidence are coincident with a decrease in lower tropospheric stability (â0.9 ± 0.4 KKâ1) and low cloud cover (âŒâ6% Kâ1). This leads to a warming associated with the weakening in the shortwave cooling effect of clouds (4.2 ± 1.9 Wmâ2Kâ1), broadly consistent with model calculations. In contrast, warmer SSTs in regions of strong convection are coincident with an increase in upper tropospheric humidity (3.2 ± 1.5% Kâ1). In this scenario, the dominant effect is the enhancement of the warming longwave cloud radiative effect (3.8 ± 3.0 Wmâ2Kâ1) from an increase in high cloud cover (âŒ7% Kâ1), though changes in the net (longwave and shortwave) effect are not statistically significant (p < 0.003). Our observational evidence supports the existence of mechanisms linking contrasting atmospheric responses to patterns in SST, mechanisms which have been linked to climate sensitivity.Publisher PDFPeer reviewe
Observed and CMIP5âSimulated Radiative Flux Variability Over West Africa
We explore the ability of general circulation models in the Coupled Model Intercomparison Project (CMIP5) to recreate observed seasonal variability in topâofâtheâatmosphere and surface radiation fluxes over West Africa. This tests CMIP5 models' ability to describe the radiative energy partitioning, which is fundamental to our understanding of the current climate and its future changes. We use 15 years of the monthly Clouds and the Earth's Radiant Energy System Energy Balanced and Filled (EBAF) product, alongside other satellite, reanalysis, and surface station products. We find that the CMIP5 multimodel mean is generally within the reference product range, with annual mean CMIP5 multimodel meanâEBAF of â0.5 W mâ2 for topâofâtheâatmosphere reflected shortwave radiation, and 4.6 W mâ2 in outgoing longwave radiation over West Africa. However, the range in annual mean of the model seasonal cycles is large (37.2 and 34.0 W mâ2 for reflected shortwave radiation and outgoing longwave radiation, respectively). We use seasonal and regional contrasts in allâsky fluxes to infer that the representation of the West African monsoon in numerical models affects radiative energy partitioning. Using clearâsky surface fluxes, we find that the models tend to have more downwelling shortwave and less downwelling longwave radiation than EBAF, consistent with past research. We find models that are drier and have lower aerosol loading tend to show the largest differences. We find evidence that aerosol variability has a larger effect in modulating downwelling shortwave radiation than water vapor in EBAF, while the opposite effect is seen in the majority of CMIP5 models.ISSN:2333-508
Financial cost of lymphedema borne by women with breast cancer
Psycho-Oncology Published by John Wiley & Sons Ltd.Objective: Our study examines the financial cost of lymphedema following a diagnosis of breast cancer and addresses a significant knowledge gap regarding the additional impact of lymphedema on breast cancer survivors. Methods: An online national survey was conducted with 361 women who had either breast cancer without lymphedema (BC) (group 1, n = 209) or breast cancer with lymphedema (BC+LE) (group 2, n = 152). Participant recruitment was supported by the Breast Cancer Network Australia and the Australasian Lymphology Association. Results: Both breast cancer and lymphedema result in significant out-of-pocket financial costs borne by women. Of patients with BC+LE, 80% indicated that their breast cancer diagnosis had affected them financially compared with 67% in the BC group (P \u3c .020). For patients with lymphedema, over half (56%) indicated that this specific additional diagnosis to their breast cancer affected them financially and that costs increased with lymphedema severity. The cost of compression garments formed a large proportion of these costs (40.1%). The average number of attendances to a therapist each year was 5.8 (range, 0-45). Twenty-five patients (16.4%) had an episode of cellulitis in the past year. The incidence of cellulitis was 7.7% in 91 patients with subclinical or mild lymphedema compared with 29.5% of 61 patients with more extensive lymphedema (P \u3c .001). The average out-of-pocket financial cost of lymphedema care borne by women was A207 for subclinical lymphedema to over A$1400 for moderate or severe lymphedema. Conclusions: This study identifies an additional detrimental effect of lymphedema on women in terms of financial costs
Polymyalgia rheumatica shows metabolomic alterations that are further altered by glucocorticoid treatment:Identification of metabolic correlates of fatigue
OBJECTIVE: In polymyalgia rheumatica (PMR), glucocorticoids (GCs) relieve pain and stiffness, but fatigue may persist. We aimed to explore the effect of disease, GCs and PMR symptoms in the metabolite signatures of peripheral blood from patients with PMR or the related disease, giant cell arteritis (GCA).METHODS: Nuclear magnetic resonance spectroscopy was performed on serum from 40 patients with untreated PMR, 84 with new-onset confirmed GCA, and 53 with suspected GCA who later were clinically confirmed non-GCA, and 39 age-matched controls. Further samples from PMR patients were taken one and six months into glucocorticoid therapy to explore relationship of metabolites to persistent fatigue. 100 metabolites were identified using Chenomx and statistical analysis performed in SIMCA-P to examine the relationship between metabolic profiles and, disease, GC treatment or symptoms.RESULTS: The metabolite signature of patients with PMR and GCA differed from that of age-matched non-inflammatory controls (R2 > 0.7). There was a smaller separation between patients with clinically confirmed GCA and those with suspected GCA who later were clinically confirmed non-GCA (R2 = 0.135). In PMR, metabolite signatures were further altered with glucocorticoid treatment (R2 = 0.42) but did not return to that seen in controls. Metabolites correlated with CRP, pain, stiffness, and fatigue (R 2 â„ 0.39). CRP, pain, and stiffness declined with treatment and were associated with 3-hydroxybutyrate and acetoacetate, but fatigue did not. Metabolites differentiated patients with high and low fatigue both before and after treatment (R2 > 0.9). Low serum glutamine was predictive of high fatigue at both time points (0.79-fold change). CONCLUSION: PMR and GCA alter the metabolite signature. In PMR, this is further altered by glucocorticoid therapy. Treatment-induced metabolite changes were linked to measures of inflammation (CRP, pain and stiffness), but not to fatigue. Furthermore, metabolite signatures distinguished patients with high or low fatigue.</p
"I suddenly felt I'd aged": A qualitative study of patient experiences of polymyalgia rheumatica (PMR).
To explore patient experiences of living with, and receiving treatment for, PMR
Imaging of giant cell arteritis â recent advances
Imaging is increasingly being used to guide clinical decision-making in patients with giant cell arteritis (GCA). While ultrasound has been rapidly adopted in fast-track clinics worldwide as an alternative to temporal artery biopsy for the diagnosis of cranial disease, whole-body PET/CT is emerging as a potential gold standard test for establishing large vessel involvement. However, many unanswered questions remain about the optimal approach to imaging in GCA. For example, it is uncertain how best to monitor disease activity, given there is frequent discordance between imaging findings and conventional disease activity measures, and imaging changes typically fail to resolve completely with treatment. This chapter addresses the current body of evidence for the use of imaging modalities in GCA across the spectrum of diagnosis, monitoring disease activity, and long-term surveillance for structural changes of aortic dilatation and aneurysm formation and provides suggestions for future research directions
Life-long epigenetic programming of cortical architecture by maternal âWesternâ diet during pregnancy
Funding: European Research Council (SECRET-CELLS, ERC-2015-AdG-695136; T.H.); Wellcome Trust grant number 094476/Z/10/Z, which funded the purchase of the TripleTOF 5600 mass spectrometer at the BSRC Mass Spectrometry and Proteomics Facility, University of St. Andrews.The evolution of human diets led to preferences toward polyunsaturated fatty acid (PUFA) content with âWesternâ diets enriched in Ï-6 PUFAs. Mounting evidence points to Ï-6 PUFA excess limiting metabolic and cognitive processes that define longevity in humans. When chosen during pregnancy, Ï-6 PUFA-enriched âWesternâ diets can reprogram maternal bodily metabolism with maternal nutrient supply precipitating the body-wide imprinting of molecular and cellular adaptations at the level of long-range intercellular signaling networks in the unborn fetus. Even though unfavorable neurological outcomes are amongst the most common complications of intrauterine Ï-6 PUFA excess, cellular underpinnings of life-long modifications to brain architecture remain unknown. Here, we show that nutritional Ï-6 PUFA-derived endocannabinoids desensitize CB1 cannabinoid receptors, thus inducing epigenetic repression of transcriptional regulatory networks controlling neuronal differentiation. We found that cortical neurons lose their positional identity and axonal selectivity when mouse fetuses are exposed to excess Ï-6 PUFAs in utero. Conversion of Ï-6 PUFAs into endocannabinoids disrupted the temporal precision of signaling at neuronal CB1 cannabinoid receptors, chiefly deregulating Stat3-dependent transcriptional cascades otherwise required to execute neuronal differentiation programs. Global proteomics identified the immunoglobulin family of cell adhesion molecules (IgCAMs) as direct substrates, with DNA methylation and chromatin accessibility profiling uncovering epigenetic reprogramming at >1400 sites in neurons after prolonged cannabinoid exposure. We found anxiety and depression-like behavioral traits to manifest in adult offspring, which is consistent with genetic models of reduced IgCAM expression, to suggest causality for cortical wiring defects. Overall, our data uncover a regulatory mechanism whose disruption by maternal food choices could limit an offspringâs brain function for life.PostprintPeer reviewe
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